Fractional Flow Reserve

Fractional Flow Reserve (FFR) is a tool that is used by an interventional cardiologist to determine whether or not a blockage that is moderate to severe on angiography is physiologically or clinically significant. In other words, some blockages may not necessarily cause enough decrease in oxygenated blood flow to the heart to lead to ischemia (a deficiency of blood supply to the heart caused by blood restriction).

FFR measures the pressure differential across a blockage. If a blockage is severe enough to cause ischemia, the pressure passed the blockage will be less than the pressure in the beginning of the artery. This test is performed by placing a wire in the artery that has a pressure transducer on the tip. After administering a medicine (adenosine) to dilate and increase the blood flow to the heart, pressures are measured in the normal part of the artery and in the section of the artery where there is a blockage. A ratio is then calculated and if it falls below 0.75 then there is very high likelihood that the blockage can lead to ischemia. Revascularization with stenting or open heart surgery are treatment options. If the FFR value is greater than 0.80, the blockage can be treated with optimal medical therapy alone.